Because of the shortage of the energy and the strict requirements of vehicles to be environment friendly, automobile manufacturers have begun to focus on the hybrid vehicles. Moreover, hybrid vehicles manufacturers have combined the internal-combustion engine, which has great power performance, with the electric motor, which is environmental friendly. Therefore, many car manufacturers have invested great manpower and financial resources in the research and development of hybrid vehicles.
In hybrid vehicles, there are two common power sources, namely, the motor, which is driven by electricity, and the internal-combustion engine, which is driven by fuel. According to different operating modes, the hybrid power driving system is conventionally divided into a serial driving system, a parallel driving system, and a serial and parallel driving system. In the serial driving system, the engine drives the electric motor to generate electricity, and the generated power drives the motor to supply power for the vehicle.
In the parallel driving system, the engine and the motor both drive the wheels. Different ways of using the two power sources can be selected according to different driving modes. However, the above-mentioned driving modes are relatively simple and do not make full use of the environmental friendly and energy saving features, and thus such systems are limited
Chinese application CN2693516Y discloses a driving system for the hybrid power vehicles, as shown in FIG. 1. The driving system includes an engine 100, a motor 200 and a planetary gear mechanism, where the planetary gear mechanism includes an internal ring gear 400, a planet carrier 500, which carries the planet gears, and a sun gear 600. The motor 200 transmits the power to the internal ring gear 400 via a gear 300, and the engine 100 may transmit the power to sun gear 600, and power from both are combined via the planet carrier.
It can be seen from the drawings and description of CN2693516Y that because the motor 200 and engine 1 transmit power to different components of the planetary gear mechanism, multiple brake and clutches are required to work under multiple working modes effectively. Therefore, the above driving system has many components, and the structure is relatively complex, rendering precise control of the system difficult.